The term “near field communication” (or “NFC”) generally encompasses short range wireless technology using magnetic field induction, often but not exclusively using the globally available and unlicensed radio frequency band of 13.56 MHz (see ISO/IEC 18092/ECMA-340 and ISO/IEC 21481/ECMA-352). NFC builds upon the same basic technology of proximity RFID tags and contactless smartcards. Such magnetic field induction techniques are a deviation from conventional transmitting devices that produce radio frequency (RF) plane waves that propagate through free space. In NFC, a transmitting device uses a transducer to modulate signals in a magnetic field that remains relatively localized around the device. Information is communicated or coupled through the magnetic field by sensing time varying fields or fluctuations using a similarly designed transducer in a receiving device. Although a small amount of RF energy inevitably flows from the transducer in the transmitting device, the majority of the energy is stored in the form of a magnetic field.
Exploiting these properties, NFC-enabled mobile devices can provide certain advantages that are not available in purely RF-based communications. These advantages arise from the fact that the signals produced in NFC attenuate as a function of 1/r6, which is much larger than the signals associated with RF fields (a function of 1/r2). This large amount of attenuation, gives NFC a relatively short communication range or communication “bubble” of about 5-10 cm. Outside of this bubble, communications are very difficult to intercept or eavesdrop on. This large attenuation also prevents NFC-enabled mobile devices from being as susceptible to overlapping frequency spectra from other devices. Thus, two or more devices can sidestep the more complicated set up procedures associated with traditional short range wireless communications (e.g., Bluetooth or Wi-Fi). For example, NFC-enabled mobile devices do not need to identify a secure channel or a common frequency band on which to communicate.
NFC-enabled devices can be used in many applications, such as electronic payment, information retrieval, and short range data transmitting. There are generally two different kinds of NFC devices: active or passive. An active NFC device provides power to an internally located transducer. When modulated, the transducer creates a signal in a magnetic field and this signal can in turn be received by a target device. Passive devices, on the other hand, use the broadcast signal from an active device for power and can therefore only communicate when they are in the presence of an active device. In general, NFC-enabled devices are active devices that include a transducer and an NFC-enabled chipset. For example, a mobile device can function as a smart card that can be used for electronic payment or as a card reader that can be used to read information from NFC tags (embedded in a poster, a kiosk, or other type of stationary device). NFC-enabled mobile devices can also set up short range wireless links with other devices. Despite being slower than some traditional short range communications, NFC can transfer information (e.g., a text or picture file) at respectable speeds of up to 424 KB/s. If larger amounts of data need to be transferred, a device can use NFC to set up an RF link. For example, Bluetooth v2.1+EDR supports session set up using an out of band (OOB) NFC link to exchange authentication, encryption, and other types of session information (see, Specification of the Bluetooth System, Jul. 26, 2007). Such OOB links can eliminate complicated and time-intensive setup and encryption procedures.
Although NFC is a very promising technology, current attempts to integrate NFC within a device have not completely addressed at least some of problems related to using devices as a short range communication tool. In particular, NFC by itself does not alleviate the often cumbersome and awkward task of entering commands and data into a device. For example, some cellular telephones are enabled with NFC capability. Such devices tend to be compact, having small display screens and limited sized keypads. When exchanging data between such devices, users need to use these compact displays and keypads to access menus and input a variety of commands before data will begin to transmit. For example, transmitting electronic contact information to another user can be an involved task. To find contact information, users typically have to use their keypad to navigate to a menu that displays all of their contacts and then use the keypad again to select an individual contact from this menu. Once the appropriate contact has been located, users need to select the contact and then indicate that they want to transmit the contact data to another device. To do this, users typically have to navigate through additional menus and input further keypad entries to initiate data transmission. Operating the compact display and keypad can be tedious and frustrating, especially when keys are accidentally depressed. As another example, it can also be difficult to use mobile device displays and keypads to organize and arrange data on a mobile device. For example, users can use the short range communication features on their mobile devices to collect hundreds or even thousands of electronic contacts. Some of these contacts may be electronic business cards (e.g., collected at a business conference or a seminar) and other contacts may be those of personal acquaintances (e.g., friends, family members, members of a sports club, etc.). Despite having acquired this data, given the nature of mobile device displays and keypads, it is difficult for a user to present or recall this information in a meaningful way (e.g., organized by type, group, date, etc.). Thus, even though NFC can allow mobile devices to collect exhaustive amount of data, it still leaves the user with the Herculean task of organizing and arranging the data after it has been collected.